* doc/tree-ssa.texi (Interfaces): Describe low vs. high GIMPLE.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@111286 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 988eed4..afb2bbe 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2006-02-20  Ben Elliston  <bje@au.ibm.com>
+
+       * doc/tree-ssa.texi (Interfaces): Describe low vs. high GIMPLE.
+
 2006-02-19  Roger Sayle  <roger@eyesopen.com>
            Steven Bosscher  <stevenb.gcc@gmail.com>
 

diff --git a/gcc/doc/tree-ssa.texi b/gcc/doc/tree-ssa.texi
index 77a2f0a..ef2bb8a 100644 (file)
--- a/gcc/doc/tree-ssa.texi
+++ b/gcc/doc/tree-ssa.texi
@@ -132,6 +132,11 @@ convert the front end trees to GIMPLE@.  Usually such a hook will involve
 much of the same code for expanding front end trees to RTL@.  This function
 can return fully lowered GIMPLE, or it can return GENERIC trees and let the
 main gimplifier lower them the rest of the way; this is often simpler.
+GIMPLE that is not fully lowered is known as ``high GIMPLE'' and
+consists of the IL before the pass @code{pass_lower_cf}.  High GIMPLE
+still contains lexical scopes and nested expressions, while low GIMPLE
+exposes all of the implicit jumps for control expressions like
+@code{COND_EXPR}.
 
 The C and C++ front ends currently convert directly from front end
 trees to GIMPLE, and hand that off to the back end rather than first